Z44 THE UNIVERSITY SCIENCE BULLETIN. 
was killed and the stomach seen to be packed with green 
chlorophyll. The contents of this stomach were fixed in 8 per 
cent formaldehyde plus copper acetate, and mounted in glyc- 
erine jelly, together with mounts of the Spirogyra before and 
after being foraged over by the bug. Drawings of these prep- 
arations are shown on plate XXX. The next day the ex- 
periment was repeated with two first instar nymphs of the 
same species. They, too, proceeded to feed at once as the adult 
had done. . 
CULTURE 16217. (Ground Elodea.) . 
History and Diagnosis Ground-up tips of E'odea and changed water 
repeatedly to wash out the free green chlorophyll matter. Studies of the 
grindings show Elodea, bits of tissue and single cells. Scenedesmus, 
threads of Gonatozygon and Oscellatoria, diatoms, large and small, a 
few heterotrichs, etc. 
ee, 
Corixids added. Every examination made of the stomach contents of 
the bugs after foraging here showed the tract packed with green ma- 
terial. This consisted of cells of Elodea, filaments of Oscellatoria and — 
Gonatozygon, desmids and the like. One A. alternata contained a thread ~ 
of Gonatozygon 1 mm. long. Splendid demonstrations, all of them, of the | 
plant feeding tendencies of these bugs. 
CULTURE 17129. A. (Ground Cattail.) 
History and Diagnosis. Gathered some dead cattail leaves from the — 
marsh hy the Field Station. Soaked them in water for a few days and © 
then ground them up by means of a meat grinder. The result was a 
flocculent brown mass cf fine matter. This material was ground up on — 
May 9 and the water changed frequently until the 11th, when Corixids, 
adult and nymphs, were added. They began foraging promptly. Ten 
days later they were still doing nicely. Examination of the forage 
showed much finely divided tissue, some Algz, mostly unicellular, such 
as Tetraspora and Englene. The rotifers, dead and alive, make up the 
bulk of the animals. There are plenty of the cellulose tissue of the cat- 
tail, bits no larger than the Alge. 
Corixids Added. The examination of the stomachs of the bugs always | 
showed them filled with brownish material, superficially like the forage. 
A close examination, however, indicated the atsence of Typha tissue, and 
the abundance of the ramate jaw parts of rotifers. Much brown matter 
that could not be analyzed, and mixed with it the green cells of the 
Tetraspora, Englene and some filamentous Alge. Even the large Arcto- 
corixa interrupta avoided taking in the Typha tissue, although it ate bits 
of Algz of larger dimension. The ground Typha serves as a stock for 
the growth of organisms eaten by the boatmen. 
CULTURE 17129 B. (Ground Cattail, sterile.) 
History and Diagnosis. Same as in 17129A. Boiled this repeatedly to 
sterilize it. Did not use the sterilizer, however, so the ground Typha 
soon spoiled even if boiled. . 
